iOS 中的冒泡、选择、快速、插入排序算法

不喜勿喷, 不吝指教

冒泡排序

若是排序结果不对，数组取值判断的时候arr[i]加上类型转化[arr[i] intValue]

//冒泡降序排序
- (void)bubbleDescendingSort:(NSMutableArray *)arr {
    for (int i = 0; i < arr.count; i ++) {
        for (int j = 0; j < arr.count - 1 - i; j ++) {
            if ([arr[j] intValue] < [arr[j+1] intValue]) {
                int num = [arr[j] intValue];
                arr[j] = arr[j+1];
                arr[j+1] = [NSNumber numberWithInt:num];
            }
        }
    }
    NSLog(@"冒泡降序排序后结果：%@", arr);
}
//冒泡升序排序
- (void)bubbleAscendingSort:(NSMutableArray *)arr {
    for (int i = 0; i < arr.count; i ++) {
        for (int j = 0; j < arr.count - 1 -i; j ++) {
            if ([arr[j] intValue] > [arr[j+1] intValue]) {
                    [arr exchangeObjectAtIndex:j+1 withObjectAtIndex:j];
            }
        }
    }
    NSLog(@"冒泡升序排序后结果：%@", arr);
}

选择排序

//选择降序排序
- (void)selectionDescendingSort:(NSMutableArray *)arr {
    for (int i = 0 ; i < arr.count; i ++) {
        for (int j = i+1; j < arr.count; j ++) {
            if (arr[i] < arr[j]) {
                int num = [arr[i] intValue];
                arr[i] = arr[j];
                arr[j] = [NSNumber numberWithInt:num];
            }
        }
    }
    NSLog(@"选择降序排序后结果：%@", arr);
}
//选择升序排序
- (void)selectionAscendingSort:(NSMutableArray *)arr {
    for (int i = 0; i < arr.count; i ++) {
        for (int j = i +1; j < arr.count; j ++) {
            if (arr[i] > arr[j]) {
                [arr exchangeObjectAtIndex:i withObjectAtIndex:j];
            }
        }
    }
    NSLog(@"选择升序排序后结果：%@", arr);
}

插入排序

//插入升序排序
- (void)insertAscendingSort:(NSMutableArray *)arr {
    for (int i = 1; i < arr.count ; i ++) {
        int num = [arr[i] intValue];
        for (int j = i - 1; j >= 0 && num < [arr[j] intValue]; j -- ) {
            arr[j+1] = arr[j];
            arr[j] = [NSNumber numberWithInt:num];
            NSString * str = [arr componentsJoinedByString:@","];
            NSLog(@"------------->结果：%@",str);
        }
    }
    NSLog(@"插入升序排序结果：%@",arr);
}
//插入降序排序
- (void)insertDescendingSort:(NSMutableArray *)arr {
    
    
    for (int i = 1; i < arr.count; i++) {
        int j = i; //  确定当前坑的位置
        int temp = [arr[j] intValue];  //  目标出列
        while (j > 0 && temp < [arr[j - 1] intValue]) {
            arr[j] = arr[j - 1]; // 向后顶大的
            j --;  //  向前移坑
        }
        arr[j] = [NSNumber numberWithInt:temp];  //  目标进坑
    }
    NSLog(@"插入降序排序结果：%@",[[arr reverseObjectEnumerator] allObjects]);
}

快速排序

//快速升序排序
- (void)quickDescendingSort:(NSMutableArray *)arr leftIndex:(NSInteger)left rightIndex:(NSInteger)right {
    if (left < right) {
        NSInteger temNum = [self getMiddleIndex:arr leftIndex:left rightIndex:right];
        [self quickDescendingSort:arr leftIndex:left rightIndex:temNum - 1];
        [self quickDescendingSort:arr leftIndex:temNum + 1 rightIndex:right];
    }
    NSLog(@"快速升序排序结果：%@", arr);

}
- (NSInteger)getMiddleIndex:(NSMutableArray *)middleArr leftIndex:(NSInteger)left rightIndex:(NSInteger)right {
    NSInteger num = [middleArr[left] integerValue];
    while (left < right) {
        while (left < right && num <= [middleArr[right] integerValue] ) {
            right --;
        }
        if (left < right) {
            middleArr[left] = middleArr[right];
        }
        while (left < right && [middleArr[left] integerValue] <= num) {
            left ++;
        }
        if (left < right) {
            middleArr[right] = middleArr[left];
        }
    }
    middleArr[left] = [NSNumber numberWithInteger:num];
    return left;
}

参考链接:iOS 开发中常用的排序（冒泡、选择、快速、插入、希尔、归并、基数）算法